import javafx.application.Application;
import javafx.geometry.*;
import javafx.scene.layout.*;
import javafx.event.*;
import javafx.stage.*;
import javafx.scene.*;
import javafx.scene.shape.*;
import javafx.scene.paint.*;
import javafx.scene.input.*;

public class Test2 extends Application {
    public void start(Stage stage) {
        Pane pane = new Pane();
        pane.setPadding(new Insets(100));
        pane.setPrefSize(400, 200);
        pane.setPickOnBounds(false);
        final CornerRadii radii = new CornerRadii(150, 150, 150, 150, false);
        pane.setBackground(new Background(new BackgroundFill(Color.BLUE, radii, new Insets(70))));
        pane.addEventHandler(MouseEvent.MOUSE_MOVED, new EventHandler<MouseEvent>() {
            public void handle(MouseEvent e) {
                Color c = new Color(Math.random(), Math.random(), Math.random(), 1.0);
                pane.setBackground(new Background(new BackgroundFill(c, radii, new Insets(70))));
            }
        });

        Scene scene = new Scene(pane, 500, 300);
        stage.setScene(scene);
        stage.show();
    }
}